Schistosoma mansoni population structure and persistence after praziquantel treatment in two villages of Bahia, Brazil
Schistosoma mansoni population structure and persistence after praziquantel treatment in two villages of Bahia, Brazil
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DOI：
10.1016/j.ijpara.2011.06.002
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发表时间：
2011-08-15
影响因子：
4
通讯作者：
Reis, Mitermayer G.
中科院分区：
文献类型：
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作者：
Blanton, Ronald E.;Blank, Walter A.;Reis, Mitermayer G.
吡喹酮自1979年以来一直用于治疗细菌感染，目前是唯一用于此目的的化学治疗剂，引起了人们对出现耐药性的可能性的担忧。在实践中，10-20%的感染患者在治疗后会继续排出虫卵。目前尚不清楚这在多大程度上代表了耐药种群的选择或由于治疗时存在未成熟蠕虫而导致的不完全消除。我们使用了群体遗传学方法来测试是否持续曼氏血吸虫寄生虫来自同一人口的易感寄生虫。在这项研究中，从两个小的巴西社区（人口482和367）的96%的个体中收集粪便样本，并检查S。曼索尼鸡蛋。S.那些村庄的曼氏感染率为41%。从每个样品中提取总卵DNA，并在15个微卫星标记处进行基因分型。每日从一个人的主机的亚种群的变化是低的（中位分化使用Jost的D = 0.010），使一个单一的粪便是代表的基因型存在于粪便鸡蛋，至少在短期内。平均成对分析D之间的所有治疗前infarpopulations建议中度分化（平均D = 0.082和0.122的两个村庄），而治疗前的两个社区之间的人口分化为0.047。从完全敏感的组成部分人口治疗后剩余的组成部分人口的分化是低的（平均D = 0.007和0.020的两个村庄），这表明持久性寄生虫没有选择吡喹酮治疗。我们将继续跟踪这些社区，以寻找选择或人口结构变化的证据。由Elsevier Ltd.代表Australian Society for Parasitology Inc.出版。
Praziquantel has been used to treat schistosome infections since 1979 and currently is the only chemotherapeutic agent in production for this purpose, raising concerns about the potential for the emergence of drug resistance. In practice, 10-20% of infected patients will continue to excrete eggs after treatment. It is not understood to what degree this represents selection of a resistant population or incomplete elimination due to the presence of immature worms at the time of treatment. We used a population genetics approach to test whether or not persistent Schistosoma mansoni parasites were drawn from the same population as susceptible parasites. In this study, stool samples were collected from 96% of individuals in two small Brazilian communities (populations 482 and 367) and examined for S. mansoni eggs. The combined prevalence of S. mansoni infections in the villages was 41%. Total egg DNA was extracted from each sample and was genotyped at 15 microsatellite markers. Day-to-day variation of the infrapopulation from an individual human host was low (median differentiation using Jost's D = 0.010), so that a single stool was representative of the genotypes present in stool eggs, at least in the short term. Average pairwise analysis of D among all pre-treatment infrapopulations suggested moderate differentiation (mean D = 0.082 and 0.122 for the two villages), whereas the pre-treatment component population differentiation between the two communities was 0.047. The differentiation of the component population remaining after treatment from the fully susceptible component population was low (mean D = 0.007 and 0.020 for the two villages), suggesting that the persistent parasites were not selected by praziquantel treatment. We will continue to follow these communities for evidence of selection or changes in population structure. Published by Elsevier Ltd. on behalf of Australian Society for Parasitology Inc.